Biomass is a renewable organic-carbon-containing feedstock that contains plant cells and has shown promise as an economical sourced of fuel. However, this feedstock typically contains too much water and contaminants such as water-soluble salts to make it an economical alternative to common sources of fuel such as coal, petroleum, or natural gas.
Historically, through traditional mechanical/chemical processes, plants would give up a little less than 25 weight percent of their moisture. And, even if the plants were sun or kiln-dried, the natural and man-made chemicals that remain in the plant cells combine to create disruptive glazes in furnaces. Also, the remaining moisture lowers the heat-producing MMBTU per ton energy density of the feedstock thus interrupting a furnace's efficiency. Centuries of data obtained through experimentation with countless varieties of biomass materials all support the conclusion that increasingly larger increments of energy are required to achieve increasingly smaller increments of bulk density improvement. Thus, municipal waste facilities that process organic-carbon-containing feedstock, a broader class of feedstock that includes materials that contain plant cells, generally operate in an energy deficient manner that costs municipalities money. Similarly, the energy needed to process agricultural waste, also included under the general term of organic-carbon-containing feedstock, for the waste to be an effective substitute for coal or petroleum are not commercial without some sort of governmental subsidies and generally contain unsatisfactory levels of either or both water or water-soluble salts. The cost to suitably prepare such feedstock in a large enough volume to be commercially successful is expensive and currently uneconomical. Also, the suitable plant-cell-containing feedstock that is available in sufficient volume to be commercially useful generally has water-soluble salt contents that result in adverse fowling and contamination scenarios with conventional processes. Suitable land for growing a sufficient amount of energy crops to make economic sense typically are found in locations that result in high water-soluble salt content in the plant cells, i.e., often over 4000 mg/kg on a dry basis.
There is an ongoing need for a system and method of operation that can economically create processed organic-carbon-containing feedstock having a water-soluble salt content a water-soluble salt content that is decreased by at least 60% on a dry basis from that of input organic-carbon-containing feedstock and a water content of less than 20 weight percent (wt %).